Texas Instruments INA250A2PW

Overview

INA250A2PW from Texas Instruments is a bidirectional, precision current-sense amplifier with an integrated 2 mΩ shunt resistor, 500 mV/A gain, ±15 A continuous current capability at –40°C to 85°C, and 0.3% max system gain error - used in high-accuracy power rail monitoring for telecom power supplies and server PMBus-based power management.

For engineers reviewing the INA250A2PW datasheet, INA250A2PW pinout, INA250A2PW application, or INA250A2PW equivalent, this page delivers verified electrical specs, TSSOP-16 package layout, Kelvin-shunt interface details, thermal derating guidance, and validated alternative options for precision current sensing in 36-V industrial and automotive systems.

Technical Context

The INA250A2PW implements a zero-drift, 36-V common-mode input amplifier paired with a laser-trimmed 2 mΩ Kelvin-connected shunt resistor, enabling bidirectional current measurement independent of supply voltage. Its internal force-sense architecture eliminates parasitic PCB trace resistance effects, and the REF pin supports user-defined zero-current output offset for unidirectional or bidirectional operation.

It operates from 2.7 V to 36 V supply, draws ≤300 µA quiescent current, and maintains 97–110 dB CMRR over –40°C to 125°C. The device's 4.5 mΩ total IN+–IN– package resistance defines thermal limits, with continuous current derated from ±15 A at 85°C ambient to ±10 A at 125°C ambient per Figure 7-1.

Key Specifications

Pinout & Package

Packaged in a 16-pin TSSOP (PW), the INA250A2PW features three ground pins (6, 8, 11) for low-noise analog return, dual Kelvin shunt terminals (SH+, SH–) for precision sensing, and separate VIN+/VIN– inputs to isolate measurement path from load/supply nodes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision current-sensing amplifier applications.

Compared with INA250A2PW, INA240A2PW trades integrated shunt convenience for higher common-mode range and flexibility, while MAX40086AUB+ offers lower offset and smaller footprint but halves the full-scale current sensitivity - making INA250A2PW optimal for 5–15 A industrial power monitoring where calibration-free accuracy and thermal robustness are critical.

Availability

INA250A2PW is available at Aetrix Electronics and suitable for telecom power supplies, server VRMs, solar microinverters, and automotive dual-battery systems requiring stable component supply, long-term production continuity, and guaranteed TI original packaging.

Supply support for INA250A2PW includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision signal conditioning and power management ICs.

The INA250 family was designed specifically for high-accuracy, integrated current sensing in industrial, telecom, and automotive power systems - eliminating layout variability and calibration overhead through monolithic shunt-amplifier co-design.

FAQ

What is the maximum continuous current rating for INA250A2PW at 125°C ambient?

The INA250A2PW supports ±10 A continuous current at 125°C ambient temperature, as specified in Figure 7-1 of the SBOS511C datasheet. This derating accounts for thermal limitations of the 4.5 mΩ total package resistance and junction temperature constraints. At lower ambient temperatures (e.g., 85°C), it handles ±15 A continuously. Proper PCB copper area and airflow are required to achieve these ratings.

Can INA250A2PW measure bidirectional current without external components?

Yes, the INA250A2PW supports true bidirectional current measurement using only the REF pin. By applying a mid-supply reference voltage (e.g., 2.5 V on a 5 V system) to REF, the output centers at that voltage - positive current increases output above REF, negative current decreases it below REF. No external op-amps or level-shifters are needed, and the device maintains 500 mV/A sensitivity in both directions.

What is the purpose of the SH+ and SH– pins on INA250A2PW?

The SH+ and SH– pins provide direct Kelvin access to the internal 2 mΩ shunt resistor's force terminals. They are intended for optional RC filtering to suppress high-frequency noise - if no filtering is needed, SH+ connects to VIN+ and SH– connects to VIN–. These pins must not be left floating, and they are not intended for use as standalone shunt terminals; the integrated resistor is calibrated only with the internal amplifier.

How does the gain error specification of INA250A2PW account for the integrated shunt?

The ±0.3% max system gain error for INA250A2PW includes both the amplifier's gain error and the integrated 2 mΩ shunt's ±0.1% tolerance - it is a fully characterized, monolithic system specification. Unlike discrete shunt+amplifier solutions, this error is guaranteed without user calibration because TI laser-trims both elements together during final test, ensuring matched temperature drift and initial accuracy.

Is INA250A2PW compatible with 3.3 V logic systems?

Yes, INA250A2PW operates from 2.7 V to 36 V supply, making it fully compatible with 3.3 V systems. Its output swings to within 50 mV of GND and within 0.2 V of VS, so with VS = 3.3 V, the output range is approximately 0.05 V to 3.1 V - sufficient to drive most 12-bit SAR or delta-sigma ADCs directly. Quiescent current remains ≤300 µA across this supply range.